It is found that use of cordless telephones is becoming more and more popular because of the advantages that such telephones are convenient to carry and can be used at any time and any place. Cordless telephones for use with a telephone set in the family and mobile telephone units are well known and both are characterized in that a handset which works to convert sound into electromagnetic waves and in the opposite way is used for communication. Since an antenna for both receiving and transmitting is required for sound signal transmission through electromagnetic waves, the antenna for transmitting and receiving electromagnetic waves for the cordless telephones is just like what a barrel is for the hand guns and gloves for the baseballs. As shown in FIG. 1, conventional cordless telephones consist primarily of a high frequency connector A, a rotating joint F, an antenna rod I, and an induction coil C, in which the rotating joint F comprises a rotating head cover D, a swivel head G, and a swinging head H, the antenna rod I being pivoted to the upper end of the swivel head G by means of the swinging head H, the lower end of the swivel head G being fitted into the rotating head cover D by a catcher E which has provided on its periphery with a plurality of longitudinal grooves and protrusions, the rotating head cover D being screwed onto the high frequency connector A, the lower end of the catcher E being formed with a hole at its center for holding the induction coil C, the upper and lower ends of the induction coil C being formed, respectively, with a short section projecting vertically from the center thereof, with the upper end being securely fitted into the holding hole on the lower end of the catcher E and the lower end being securely fitted into the holding hole on a central pin seat B, wherein the opening of the catcher E is suitably expanded under the action of the grooves so as to catch the swivel head G and the catcher E, after being fastened to the swivel head G, is squeezed into the rotating head cover D to be fixed in the rotating head cover D and to have the swivel head G suitably clamped so as to provide a holding force for directional adjustment of the antenna rod I.
However, said holding force by the catcher E against the swivel head G results from the resilient deformation effected when being pressed into the rotating head cover D. The catcher E and the swivel head G are both made from a metal material such that slight deformation produces considerable stress and once the resilient deformation is offset by the wear due to rotation, the holding force would no longer exist such that the antenna rod I would become loose. In addition, both ends of the induction coil C make contact by insertion with only small contacting surface, hence there are the drawbacks that not only they are easily subject to wear but also signal transmission is undesirable.